Magneto-switchboard cord-circuit.



01 M. LEIGH.

MAGNETO SWITCHBOARD CORD CIRCUIT.

APPLICATION FILED OCT. 19. 1914.

2 SHEETS-SHEET I.

W QwanZ/Z; flak 1 M i fig COLUMBIA PLANOURAPH 60.,WASHINGTON, D. c.

Patented Dec. 21, 1915.

0. M. LEIGH.

MAGNETO SWI-TCHBOARD CORD CIRCUIT.

' APPLICATION FILED OCT-19, I914- 1,165,336. Patented Dec. 21, 1915.

2 SHEETSSHEET 2- COLUMBIA PmNOGkAPu CO.,WASH|NIZTON, D. c.

,TUNiTE s FIQE.

OSCAR M. LEIGH, OF GENOA, ILLINOIS, ASSIGNOR TO ORACR-AFT, LEIGH ELECTRIC 7 COMPANY, OF GENOA, ILLINOIS.

MAGNETO-SWITCI-IBOARD CORD-CIRCUIT.

Specification of Letters Patent.

Patented Dec. 21, 1915.

Application filed. October 19, 1914. Serial No. 867,405.

talking and in which alocal battery may be used for signaling or :a magneto generator may be used for signaling. T

My invention concerns itself with cord circuits for use in connection with switch boards having means responsive to impulses or pulsations of current to give to the operator a clearing out signaling indication and also a recall signal.

My invention also concerns itself with the mechanical structure of the signaling device.

I will explain my invention more indetail by referring to the accompanying draw-' ings in which Figure 1 represents diagrammatically a telephone system constructed in accordance with my invention; Fig. 2 is a side view of a cord circuit signaling device constructed in accordance with my invention; Fig. 3 is a longitudinal sectional view thereof; Fig. 4 is a top view thereof, and Fig. 5 is a bottom view thereof.

In Fig. 1, I illustrate the ordinary local battery telephone instrument having the customary receiver 1, transmitter 2, battery 3, generator 4, induction coil 5, switch hook 6, and ringer 7. This instrument extends by way of the line conductors 8 and 9 to the central station where it terminates in a ack 10 associated with the line drop 11. My improved cord circuit which is the subject matter of this invention has the calling plug 12 and answering plug 13 united by the cord strands 14 and 15 respectively. Condensers 16 and 17 are interposed to obtain a double supervisory signaling indication. The customary ringing key 18 is shown as well as the listening key 19, which listening key has a pair of additional springs 20 and 21 actuated each time the listening key is actuated and whose purpose will presently appear.

Bridged across the calling side of the cord clrcuit 1s a supervisory relay 22 and a s1m1- 'lar relay 23 is bridged across the answering side of the cord circuit. These supervisory relays through the agency of their armatures 24 are adapted respectively to control the circuit through low wound clearing out drops 25 and 26 respectively. These drops are each provided with a restoring coil 27 to restore the drop shutter 28 whenever these coils 27 are included in circuit with the bat 'tery 29, which occurs whenever springs 20 and 21 are closed due to the actuation of thell'stening key 19. Thus the drop shutters 28 are always in their normally unactuated position immediately after the listening key .1s operated so that this cord circuit after the starting of. a call is in proper condition to receive signals. The circuit through the magnets 25 and 26 passes respectively through associated lamps 30 and 31. The

.circuit through these instrumentalities for the calling side of the cord circuit being for instance traced from the battery 29, through the lamp 30, through the low wound drop 25, armature 24 of the relay 22, and back to the other terminal of the battery 29.

It will thus be seen that whenever the relay 22 is actuated the drop coil 25 actuates its shutter 28 and the lamp 3O burns during the time that the armature 24 remains attracted. Now when the original clearing out signal is sent as by one turn of the generator 4, then the drop shutter of the electromagnet 25 is actuated and the lamp 30 temporarily is illuminated. Now should the subscriber however desire a further connection before the cord circuit is restored, this subscriber would have no means of calling the attention of the operator if it were not for the presence of the lamp 30. Even though the shutter 28 is in its actuated condition, if the subscriber actuates the generator 4, this will operate the relay 22 to thereby illuminate the lamp 30 and call the operators attention to the fact that the subscriber wishes to recall. Through the use of the relay 22 I am enabled to obtain the necessary fine adjustment required in order to permit the reception of impulses in such manner as to insure proper contact of its armature, whereby to properly illuminate the lamp 30. Instead of the substation circontinued operation of the relay 22 and hence the lamp 30.

In Figs. 2, 3, 4 and 5, I show more in de tail the particular supervisory structure comprising the elements 25, 27, 2S and 30. These elements are all carried by a front plate 32 to which is attached av framework 33. On top of this framework the shutter controlling electrcmagnet is mounted. An armature 3'-l pivoted between the sides of the frameworknormally holds the shutter 28. A finger 35 projects downwardly from the shutter and is adapted to be engaged by an arm 36 fastened to the armature 87 of the magnet 27. The arm 36 restores the shutter 28 whenever the electromagnet 27 is energized. Rearwardly of the front plate 32 there also extends two insulated springs 38 and 39 between which the lamp 80 is mountedso that this lamp 30 can be seen through the opening 40 provided in the front plate.

There is thus provided a very homogeneous self-contained structure capable of fulfilling all of the requirements mentioned herein, namely the ordinary clearing out facilities, automatic shutter restoring facilities and recall facilities.

Frcm what has been described my invention will be readily clear to those skilled in the art, and

What I therefore claim as new and desire to secure by Letters Patent is:

1. A telephone system comprising local battery substation instruments, and a cord circuit at the exchange, said cord circuit having a clearing out relay, an annunciator, and a lamp, said lamp and annunciator being controlled by said relay.

2. A telephone system comprisinglocal .battery substation instruments, and a cord circuit at the exchange, said cord circuit having a clearing out relay, an annunciator, and a lamp, said lamp and annunciator having their circuit controlled by said relay.

3. A telephone system comprising local battery substation instruments, and a cord circuit at the exchange, said cord circuit having a clearing out relay, an annunciator,

and a lamp, said lamp and annunciator being serially included in a circuit controlled by said relay.

4. A telephone system comprising local I battery substation instruments, and a cord c1rcu1t at the exchange, said cord c1rcu1t having a clearing out relay, an annunciator,

and a lamp, said lamp and annunciator being serially included in a circuit controlled by said relay, said annunciatorhaving a low resistance Winding.

In witness whereof, I hereunto subscribe my name this 1st day of October, A. D.,-,

OSCAR H. LEIGH. IVitnesses MAX W. ZABEL, IIAZEL A. J oxns.

Copies of this patent may be attained for five cents each,'by addressing the Commissioner of Patents, Washington, D. C.- 

